You can search and filter your contacts two ways within Message: simple search and advanced search.
Simple search is helpful when you're looking for a contact and you know their name or phone number. To find the contact, type that contact's name or number in the search bar. Hit enter on your keyboard and the results to the right will refresh.
Advanced search is most useful when you want to filter your contacts by certain data criteria. To start, click the advanced search link underneath the search bar.
A window will appear in the center of the page. Click Add Criteria to begin. From here, you will be prompted to choose a variable that's available in the selected programs (to adjust the programs you have selected, click out of the window and check or uncheck a program at the left). Next, you'll be able to identify how you want to search within that variable (equals, does not equal, contains, does not contain, etc). Finally, you will select the value(s) you are searching for. After the search criteria has been set, you can add on additional variables by clicking Add Criteria. If the search is complete, click Search to view your results.
An example of an advanced search - filtering for any contacts with a GPA above a 3.0.
If you want to save the search for future use, click on the arrow next to the search bar and type in a name when prompted. Once you save it, you can come back and run it again by clicking on the same arrow.
If you have more than one program selected, only the variables that are in all programs will appear as search options, so keep that in mind if items appear to be missing.